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/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.activemq.transport.discovery.rendezvous;
import java.io.IOException;
import java.net.InetAddress;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.activemq.jmdns.JmDNS;
public final class JmDNSFactory {
static Map registry = new HashMap();
static class UsageTracker {
AtomicInteger count = new AtomicInteger(0);
JmDNS jmDNS;
}
private JmDNSFactory() {
}
static synchronized JmDNS create(final InetAddress address) throws IOException {
UsageTracker tracker = registry.get(address);
if (tracker == null) {
tracker = new UsageTracker();
tracker.jmDNS = new JmDNS(address) {
public void close() {
if (onClose(address)) {
super.close();
}
}
};
registry.put(address, tracker);
}
tracker.count.incrementAndGet();
return tracker.jmDNS;
}
static synchronized boolean onClose(InetAddress address) {
UsageTracker tracker = registry.get(address);
if (tracker != null) {
if (tracker.count.decrementAndGet() == 0) {
registry.remove(address);
return true;
}
}
return false;
}
}